"Almost 10 years ago, during the last week of my mother's life, I told my friends and family that if I ever played my own concerts again, I would make sure to do a free one for NHS nurses," writes the singer.

"I can't wait. Neither can the tour crew, for entirely different reasons."

Michael made headlines last month after being filmed smoking cannabis on an ITV programme.

In October he was cautioned by police for possessing cannabis after being found in north London slumped at the wheel of his car.